For health reasons I need to cook all my own meals (gi issues) and it sounds to me like soups and chili could be pretty healthy. Think paleo....mostly.
For long days of travel (getting from NY to Newfoundland or NY to Colorado) I make ahead some stews/soups that I can take out a day or so ahead and just heat up. The ingredients and most of those soup/stews are often from our garden. Hubby likes hummus so I have a magic bullet that does that and he can dip cukes/carrots/peppers in that to his hearts content. For travel, I will also precook/grill chicken for our use and it can be added to hubby's burrito and plopped in with some veggies for me. Smoothies are quick to make and provide instant energy. I prewash garden salad ingredients and STUFF, STUFF, the refrigerator/larders with these (yeah, even to canada it worked...as they were preoccupied with the bike mace hubby had...a no no there).
Healthy food can be cheap in many ways.
Donna